SELF-ABSORPTION CORRECTIONS FOR WELL-TYPE GERMANIUM DETECTORS

Corrections for self-absorption are of vital importance to accurate determination by gamma spectrometry of radionuclides such as Pb-210, Am-241 and Th-234 which emit low energy gamma radiation. A simple theoretical model for determining the necessary corrections for well-type germanium detectors is presented. In this model, self-absorption factors are expressed in terms of the mass attenuation coefficient of the sample and a parameter characterising the well geometry. Experimental measurements of self-absorption are used to evaluate the model and to determine a semi-empirical algorithm for improved estimates of the geometrical parameter.